Sleeve hammer piano action with escapement simulator

ABSTRACT

An escapement-simulating device used in a piano action having as a striking hammer, a sleeve hammer impelled upward along a shaft by a forked lever. The escapement simulator is a spring leaf fork attached to the top side of the forked impelling lever. The upward motion of the spring leaf fork is abruptly limited by a travel stop. The forked lever and the piano key to which it is attached may continue a distance farther due to the bowing of the spring leaf fork. The incorporation of the spring leaf fork simulates the &#39;&#39;&#39;&#39;feel&#39;&#39;&#39;&#39; of an escapement as in conventional pianos.

United States Patent Robert A. Brocato 108 E. Jordan St., Shreveport, La. 7110] 792,522

Jan. 21, 1969 Feb. 16, 1971 Inventor Appl. No. Filed Patented SLEEVE HAMMER PIANO ACTION WITH [56] References Cited UNITED STATES PATENTS 2,271,460 1/1942 Miessner 84/236 2,950,642 8/1960 Sluyter 84/236 Primary Examiner-Richard B. Wilkinson Assistant Examiner-John F. Gonzales ABSTRACT: An escapement-simulating device used in a piano action having as a striking hammer, a sleeve hammer impelled upward along a shaft by a forked lever. The escapement simulator is a spring leaf fork attached to the top side of the forked impelling lever. The upward motion of the spring leaf fork is abruptly limited by a travel stop. The forked lever and the piano key to which it is attached may continue a distance farther due to the bowing of the spring leaf fork. The incorporation of the spring leaf fork simulates the feel of an escapement as in conventional pianos.

PATENTEU rm 1 6m 3.563.125 I 1 1 m ruw v INVUN'IUR ROBERT A. BROCATO This invention is concerned with piano string striking mechanisms and is an improvement upon a sleeve hammer and shaft striking mechanism described in the applicant's prior application, entitled Sliding Hammer Type Piano Action," Ser. No. 767,523.

In the sliding or sleeve-type hammer action disclosed in applicants prior application cited above, the piano striking hammer is a cylindrical annulus which has a cushion of felt on both ends or may have as a striking end, a medium soft tip of rubber or of similar substance. The cylindrical annulus is positioned concentrically on a vertical shaft which is situated beneath the piano vibratory memberwhich could be a string, rod or a reed. The shaft terminates about one-eighth inch from the vibratory member. The annulus is impelled upward along the shaft by the action of a forked lever that is manually operated by the piano key. The forked lever has only limited travel, but the cylindrical annulus proceeds all the way to strike the string or vibratory member under the influence of momentum.

The present invention is a sleeve hammer and shaft piano action which has a spring leaf fork between the impelling fork lever, to which it is attached,and the sleeve hammer. The spring leaf fork inclusion results in'an effect identical to an escapement in a piano action. The spring leaf fork makes it possible for the key movement tohave the feel that an escapement would produce. Butsince a tripping escapement jack is not used as in conventional piano actions, the spring leaf fork may be said to simulatean escapement.

Further objects and advantages of the invention .will become apparent in the course of the following detailed description when viewed together 'with the accompanying drawings of the sleeve hammer piano action with escapement simulator.

FIG. I is an elevational view of the piano action as claimed in the present invention. The same being shown in a state of equilibrium.

FIG. 2 is a view similar to FIG. 1, but showing the action with the piano key in the manually depressed state.

FIG. 3 is an exploded view of theflexible spring leaf fork and the forked impelling lever.

Referring to the accompanying drawings, wherein similar reference characters designate similar parts throughout, FIG. I is a sideview of the invention which is especially drawn so that the mechanism between onepi'ano key and corresponding vibratory member is illustrated. In FIG. I the piano key is in its usual or raised position. FIG. 2 is'a view similar to FIG. 1 except that the piano key is in the manually depressed state. The difference in this action and the action in the applicant's prior application already cited above is the utilization of a flexible spring leaf fork 9 as an escapement-simulator device and an adjustable travel stop 8. The travelstop 8 is constructed of a screw with a felt cushioned head. Adjustment is made by varying the height of the screw in the holder. Referring to FIGS. 1

and 2, the depressing of key 4 swings the forked lever 6, im-

pelling the sleeve hammer I towardthe vibratory member 2, and also raising the damper lever 5 and damper 11 from the vibratory member. The sleeve hammer I has a hammer head 13 made of felt or rubber. The forked lever is connected to the damper lever by the damper rod 10. The capstan screw 7 and the spring leaf fork travel stop 8 are adjusted in height so that the spring leaf fork 9 barely touches the'travel stop 8 when the key 4 is about one-eighth inch from the bottom of its depression and the top of hammer head 13 on hammer l is about three thirty-seconds inches beneath'the vibratory member. With an adjustment such as thisthe spring leaf fork 9 will be bowed slightly when the key is fully depressed, as pictured in FIG. 2. During the interval that the key is being pressed, the

sleeve hammer l is being impelled up shaft 3 toward the vibratory member 2 until the spring leaf fork hits the travel stop 8. The spring leaf fork tip stops immediately and the sleeve hammer continues in its movement a small distance until it hits the vibratory member. The key may continue easily beyond this point until it is fully depressed. The spring leaf fork 9 is made of a very light flexible steel so that no more force is required to bow the spring fork than to lift the sleeve hammer. The spring leaf fork 9 is screwed on the fork lever 6 by two screws 14. Another wide head screw 12 limits the upward bend of the spring fork. In FIG. 3 is shown a three dimensional view of the spring leaf fork 9 and the fork lever 6. The fork opening or slot in the fork lever is just wide enough that it will track along the shaft 3 easily. The slot in thespring leaf fork is sufficiently wide so that the spring leaf fork moves up and down with sufficient clearance so that it does not contact the shaft.

The advantage of the incorporation of the spring leaf fork is that the spring fork has a maximum velocity when it hits the travel stop. The spring tip stops instantaneously but the abrupt cessation is not transmitted through the rest of the mechanism. In effect; the spring leaf fork acts as an escapement in that after the spring fork hits the travel stop, depressing the key further does not result in further manipulation of the sleeve hammer.

Several embodiments of the invention have been described. but changes and modifications can be made without departing from the invention as defined in the claims.

Iclaim:

I. In a musical instrument which utilizes a percussion activated vibratory member as a sound source and a sleeve hammer on a shaft which is impelled upward by the action of a forked lever encompassing the shaft on the underside of the said sleeve hammer as a piano action, a spring leaf fork attached to the upper side of the said forked lever, substantially coinciding with the conformation of the said forked lever. and an adjustable upward motion stop positioned in the path of travel of the said spring leaffork and limiting its travel thereof.

2. In a musical instrument having a vibratory member as a sound source, means for striking said vibratory member to produce the sound comprising a two-member lever arrangement positioned beneath said vibratory member, one of said members constituting a key on the keyboard of said instrument, the second of said levers being responsive to the movement of said first lever for its movement, a vertically disposed shaft positioned at the end of said second mentioned lever, a flat spring carried by said second lever, the end of both said spring and said lever being bifurcated and adapted to embrace said shaft, a sleeve hammer slidably mounted on said shaft with the lower end thereof normally resting on said bifurcated spring and adapted for free movement upward and downward on said shaft upon actuating said lever key arrangement, a stop in the upward path of travel of said bifurcated spring to allow said sleeve hammer to continue movement by its own momentum on said shaft to strike said vibratory member.

3. In a musical instrument having vibratable members as a sound source, means for striking said members comprising a key arrangement consisting of two levers, one of said levers constituting the main key of the keyboard, the second of said levers being responsive to the movement of the first mentioned lever for its movement, a vertical disposed shaft beneath said vibratory member and in exact vertical alignment wherewith, a sleeve hammer slidably embracing said shaft. said second lever provided with a flat spring bifurcated at one end to receive said shaft, said sleeve hammer also resting on said spring, said first mentioned lever being pivotally arranged to impart force and speed to the end of said second mentioned lever and consequently to said sleeve hammer and a stop member limiting the upward travel of said spring. 1 

1. In a musical instrument which utilizes a percussion activated vibratory member as a sound source and a sleeve hammer on a shaft which is impelled upward by the action of a forked lever encompassing the shaft on the underside of the said sleeve hammer as a piano action, a spring leaf fork attached to the upper side of the said forked lever, substantially coinciding with the conformation of the said forked lever, and an adjustable upward motion stop positioned in the path of travel of the said spring leaf fork and limiting its travel thereof.
 2. In a musical instrument having a vibratory member as a sound source, means for striking said vibratory member to produce the sound comprising a two-member lever arrangement positioned beneath said vibratory member, one of said members constituting a key on the keyboard of said instrument, the second of said levers being responsive to the movement of said first lever for its movement, a vertically disposed shaft positioned at the end of said second mentioned lever, a flat spring carried by said second lever, the end of both said spring and said lever being bifurcated and adapted to embrace said shaft, a sleeve hammer slidably mounted on said shaft with the lower end thereof normally resting on said bifurcated spring and adapted for free movement upward and downward on said shaft upon actuating said lever key arrangement, a stop in the upward path of travel of said bifuRcated spring to allow said sleeve hammer to continue movement by its own momentum on said shaft to strike said vibratory member.
 3. In a musical instrument having vibratable members as a sound source, means for striking said members comprising a key arrangement consisting of two levers, one of said levers constituting the main key of the keyboard, the second of said levers being responsive to the movement of the first mentioned lever for its movement, a vertical disposed shaft beneath said vibratory member and in exact vertical alignment wherewith, a sleeve hammer slidably embracing said shaft, said second lever provided with a flat spring bifurcated at one end to receive said shaft, said sleeve hammer also resting on said spring, said first mentioned lever being pivotally arranged to impart force and speed to the end of said second mentioned lever and consequently to said sleeve hammer and a stop member limiting the upward travel of said spring. 